Can large-scale tree planting in China compensate for the loss of climate connectivity due to deforestation?

Extensive deforestation has been a major reason for the loss of forest connectivity, impeding species range shifts under current climate change. Over the past decades, the Chinese government launched a series of afforestation and reforestation projects to increase forest cover, yet whether the new forests can compensate for the loss of connectivity due to deforestation-and where future tree planting would be most effective-remains largely unknown. Here, we evaluate changes in climate connectivity across China's forests between 2015 and 2019. We find that China's large-scale tree planting alleviated the negative impacts of forest loss on climate connectivity, improving the extent and probability of climate connectivity by 0-0.2 degrees C and 0-0.03, respectively. The improvements were particularly obvious for species with short dispersal distances (i.e., 3 km and 10 km). Nevertheless, only similar to 55 % of the trees planted in this period could serve as stepping stones for species movement. This indicates that focusing solely on the quantitative target of forest coverage without considering the connectivity of forests may miss opportunities in tree planting to facilitate climate-induced range shifts. More attention should be paid to the spatial arrangement of tree plantations and their potential as stepping stones. We then identify priority areas for future tree planting to create effective stepping stones. Our study highlights the potential of large-scale tree planting to facilitate range shifts. Future tree-planting efforts should incorporate the need for species range shifts to achieve more biodiversity conservation benefits under climate change.